Heating apparatus



Sept. 3, 1929. H. owLEs ET A'. 1,726,527

HEATING APPARATUS `Filed Jan. l1, 1925 2 Sheets-Shet 1 f i/f LE /N VEN'TORS wf @ifo/WE Y:

SGP N3', 1929"- H. cowLEs ET AL 1,726,527

HEATING APPARATUS.

Filed Jan. 11, 1925 2 Sheets-Sheet 2 A /N VENTO/Qs 4** www K. m

Patented Sept. 3, 1929.

UNITED STATES HENRY cowLEs AND JAMES K. NoRRIs, or UTIcA, NEW YORK, AssrcNoRs, BYy MEsNE 1,726,527 PATENT OFFICE.

ASSIGNMENTS, TO NATIONAL RADIATOR CORIfORATION, OF DOVER, DELAWARE,

A CORPORATION OF DELAWARE.

.HEATING APPARATUS.

Application led January 11, 41923. Serial No.612,003.

Our invention relates to boilers or hotwater heating apparatus of the type in which auxiliary air is introduced into the combustion space for insuring complete combustion and thereby increasing efficiency and preventing smoke, and -it attains these ob]ectsk by causing the air before its delivery at the place where it is needed, to be properly heated during its passage thereto by` extending the air conducting pipe or passage in and preferably through or across a'iire gas iiue through which products of combustion are passing and whereby the air is heated to the requisite extent and thence extending it through or in close relation to a water-containing space from which the air is directly admitted to its point of mixture with the iire gases to perfect the combustion of the latter. By this means, it is practical to admit air vof adequate temperature, i. e. above the critical point or lower limit of temperature range where the` most efficient combustion is secured; without danger of burning out the air pipe.

Our invention, in its preferred form, is embodied in a sectional furnace made up .of a series of front, rear and intermediate cast, hollow, water-containing units or sections assembled to form a iirebox, rear flue space and overhead return flues, all-in communication, and provided with pipes for admitting auxiliary air, as above mentioned, which pipes deliver the air int-o the fire-gas flow, so as to perfect or stimulate the combustion reaction therein and are themselves subject to thetemperat-ure of the fire gases at points farther along in the path thereof and more remote from the region of maximum combustion.

Three forms which the apparatus may advantageously take are illustrated in thepdrawings in which Fig. 1 is a side elevation partly in section;

Fig. 2 a section on the line II-IIof Fig. 1 looking toward the rear of the furnace as indicated by the arrows, part of the front wall of the adjacent section being broken away to show the interior construction;

Fig. 3 is a. section on the line III-III Fig. 2 looking in the direction' of the arrows;

Fig. 4 is a front view of a section illustrating a modification; i

Fig. 5 is a section on the line V-V Fig. 4;

Fig. 6 is a section on the line VI-.VI Fig. 4 looking in the direction of the arrows ;y

further modified form of my invention, which is similar to that of Fig. l, but differs therefrom in the `inclusion of a removable relatively denlarged' flue-contained air-heating box; an

Fig.` 8 is a heating box.

The sectional furnace herein illustrated corresponds in general to usual furnace construction of this type-being made up of a series yof cast, hollow, water-containing units perspective view of said airvor sections 1 bolted together and suitablysup-` ported as by the base members 2 at each side of the furnace; a rear plate 3, an intermediate plate 4 and a front plate 5 with usual door and Vdamper arrangements completing the structure at the base and providing in ad-t Vance of the plate 4 the usual ash pit. These sections are provided with flue openings, which in the assembled position arealigned to form the firebox 6, below which is located the grate 7 and above which are the overhead return side lues 8 and the central rearward overhead flue 9, together with communicating-flue space 10 as indicated at the left of Fig. 1, the flow'of the combustion products as yindicated by the arrows in Fig. l being that usual in furnaces of this type. Some of the sections toward the front of the furnace provide the fireboX and all of the intermediate sections form combustion and flue space communicating with the fire-box space.v The eX- ternal contour of all sections is the same but theirv structure is not identical. The front section is provided with they usual firebox openings or feed and clean-out doors 11. The rear section forms-the rear wall of the furnace, as will be understood. An intermediate section 12 is'formed so as to produce a throat passage through which the lire gases pass from the fire-box to the flue space. This section illustrated in Figs. 1 to 3 and, which in its main features shows the preferred form of the invention, is provided with aligned vertical cored passages 13 and 14 on each side of the furnace, into which the auxiliary air pipes 15 provided with dampers 15 are inserted, the construction being the same at each side. The air pipes so placed intersect the sidelines Sand are thus subjected for a part of their length to ahigh degree of heat, the temperature ofthese flues being greater than in the center flue, but less than in the Fig. 7 is a fragmentary detail view of a fire-box or in its restrictedthroat outlet. The

e a series of downwardly delivering openings 17. The air is ldirected byv` this exit athwart the current ofburning gases.

. While the arrangement thus described is preferred, we may dispense with the air. chamber and deliver theauxiliary air directly from the pipes 15 to the combustion space adjacent anyy sectionor sections, as in the construction illustrated in Figs. 41 to 6, wherein the section'shown isone of thosein advance ofthe throat section. Such a section may be employed with the throat section of Figs. 1 to 3 or with otherthroat sections. It is cast with grooves 18, 19, preferably aligned vertically, 18 being above and 19 below the central flue space. The auxiliary air pipe 15 may be laid in these grooves lduring assembly. It is thus subjectedto a cooling action as well as to the heating effect, ofvfthe flue gases. These pipes may. be withdrawnv from the furnace after assembly. Y

The form shown in Figs. 7 and Sis amodiication of that illustrated in Figs. 1A to 3, and as to the features peculiar to Figs. 7 and 8, an improvement thereon. This construction dii'ers from that ofFigs. 1 to, 3, in that the air pipe 15does not extend through the flue, and enters it onlyl far. enough to communicate with.y a removable air-heating `box, 20 which is'placed inthe side flue and forms part of the passage for auxiliary air.` It. is enlarged relatively to the pipe 15 therebyproviding an increased area of heating surface and constituting; in effect an enlarged extension of the pipe having an outlet at its bottom which is of a smaller section than the bodyof the box 20, and is shown asl formed by. a downwardly extending nipple 21 which `fits a corresponding depression inthe-,bottom flue wall, said nipplebeing in alignment. with the passage 14 to the cross-air box 16. Should the air-heating box 20 `burn out, it` can be readily removed and replaced. through` the correspondingl flue door in the front unit 1, The duct for delivering air to the air'box or to the combustion space may include a. plurality of passages and be constituted in whole or in part by a separatelymade pipe. This arrangement of removableair--heatersmay obviously also be employed in the center flue.

In each of the forms above described, itr will. be apparent that the greater part of the air for combustion of the fuel enters through the'grate, and that allthe remainder,I

herein termed auxiliary air, is admitted at the point of greatest velocity of the gas travel and directly into such gas. By this arrangement, the pull of the chimney will maintain an adequate inflow through the auxiliary air pipes, sufficient to produce a thorough mixing and stimulated combustion. By the passage of such air through the fire-gases in the fines, at points relatively remote from the throat or region of maximum combustion, it becomes heated highly enough so that it is not cooled, by itsxsubsequent Contact with water-cooled walls, to a'temperature so low asrto be incapable of the desired instantaneous combustive reaction.k At the same time no part of theair passage, which is near the very intense heat at the throatand in the fire-box, is left lunprotected by water so'as to-be likely to burn out. It has been found that air passages `entirely surrounded by water do not heat the air to the desired point for .thev

best combustion, but by the arrangement described,.the air is adequately heated although delivered to the fire-gases from a water-cooled box or from immediate proximity to watercooled walls.

We claim as our invention 1. A sectional furnace comprising a longitudinal series of transverse hollow water-v containing sections boltedl together, having a 'grate and forming by alined openingsin adjacent sections a firebox and a longitudinaloverhead flue, and an air duct leading from the atmosphere through waterl spacel to and through said? flue, andv through water space beyond the flue to the combustion space, being water protected at and adjacent yits point of delivery to the fire gases, whereby the duct is protected against destructively high tempera-y .ture and theairI delivered by it heated to a point at which it doesnot chill the fire gases.

, 2. A sectional furnace comprising a seriesof hollow transverse water-containing sectionsy forming a longitudinally extending firebox with water-cooled walls, an overhead flue space through which products of combustion therefrom pass,..and a separately formed pipe passing imperforate through said flue space, partially water-cooled butk protected from direct contact with water and functioning in they delivery of air to the combustion space at a point beyond the flue.

3. A sectional furnace comprising a series ofv hollow water-containing sections forming a irebox and flue, and a depending wall at the rear of said firebox and whose lower edge de fines the throat through which the products of'combustion pass, the throat section or sections having a transverse water-cooled air box provided with air distributing openings adjacent the region of maximum combustion and a vduct for delivering air to said air box part ofiwhich duct is located in the flue and is thus highly heated and parts of which in advance of the flue and beyond the Hue to the air box passages opening to the atmosphere and thel other to said air box, said passages being adapted to receive a separately formed air pipe in heat exchanging relation with the walls of one of them, and said air pipe being in communication with the air box.

5. In a sectional furnace, a transverse hollow water-containing throat section having a flue opening in the upper part thereof and having below the same a depending wall ending in a transverse water-protected air delivery box defining the upper side of the throat through which fire gases are intended to pass, said unit having water-cooled passages abutting on said flue opening adapted to receive in heat exchanging contact a separately formed air pipe which extends imperforate in said iue opening from one of said passages v to the other and communicates respectively with the atmosphere and with said air box, whereby said pipe and passages being watercooled to their delivery ends are protected tion having a portion adjacent the flue open-k ing shaped to receive, and cool without direct Water contact, a separately formed pipe extending imperforate acrosssaid flue opening a and communicating with the fire box space.

7. In a sectional furnace, a transverse hollow water-containing throat section having three transversely alined iiue openings in the upper part thereof and having below the same a depending wall ending in a transverse water protected air delivery box defining the upperside of the throat through which fire gases are intended to pass, said unit having a pair of water cooled passages abutting on each side flue opening, each such pair being adapted to receive, in heat exchanging contact wlth one of its members, a separately formed air pipe which extends in the flue opening from one passage to the other and communicates respectively with the atmosphere and with said air box.

In testimony whereof, we have signed this i specification. f

HENRY COWLES. JAMES K. NORRIS. 

